diff --git a/src/base/abci/abc.c b/src/base/abci/abc.c
index b2bcada9a..fc75642d8 100644
--- a/src/base/abci/abc.c
+++ b/src/base/abci/abc.c
@@ -36828,14 +36828,15 @@ usage:
 ***********************************************************************/
 int Abc_CommandAbc9Scorr( Abc_Frame_t * pAbc, int argc, char ** argv )
 {
+    extern Gia_Man_t * Cec_ManScorrCorrespondence( Gia_Man_t * p, Cec_ParCor_t * pPars );
     extern Gia_Man_t * Gia_ManScorrDivideTest( Gia_Man_t * p, Cec_ParCor_t * pPars );
     Cec_ParCor_t Pars, * pPars = &Pars;
     Gia_Man_t * pTemp;
     int fPartition = 0;
-    int c;
+    int fUseOld = 0, c;
     Cec_ManCorSetDefaultParams( pPars );
     Extra_UtilGetoptReset();
-    while ( ( c = Extra_UtilGetopt( argc, argv, "FCPXpkrecqwvh" ) ) != EOF )
+    while ( ( c = Extra_UtilGetopt( argc, argv, "FCPXpkrecqowvh" ) ) != EOF )
     {
         switch ( c )
         {
@@ -36901,6 +36902,9 @@ int Abc_CommandAbc9Scorr( Abc_Frame_t * pAbc, int argc, char ** argv )
         case 'q':
             pPars->fStopWhenGone ^= 1;
             break;
+        case 'o':
+            fUseOld ^= 1;
+            break;
         case 'w':
             pPars->fVerboseFlops ^= 1;
             break;
@@ -36932,7 +36936,9 @@ int Abc_CommandAbc9Scorr( Abc_Frame_t * pAbc, int argc, char ** argv )
         Abc_Print( 0, "The network is combinational.\n" );
         return 0;
     }
-    if ( fPartition )
+    if ( fUseOld )
+        pTemp = Cec_ManScorrCorrespondence( pAbc->pGia, pPars );
+    else if ( fPartition )
         pTemp = Gia_ManScorrDivideTest( pAbc->pGia, pPars );
     else
         pTemp = Cec_ManLSCorrespondence( pAbc->pGia, pPars );
@@ -36940,7 +36946,7 @@ int Abc_CommandAbc9Scorr( Abc_Frame_t * pAbc, int argc, char ** argv )
     return 0;
 
 usage:
-    Abc_Print( -2, "usage: &scorr [-FCPX num] [-pkrecqwvh]\n" );
+    Abc_Print( -2, "usage: &scorr [-FCPX num] [-pkrecqowvh]\n" );
     Abc_Print( -2, "\t         performs signal correpondence computation\n" );
     Abc_Print( -2, "\t-C num : the max number of conflicts at a node [default = %d]\n", pPars->nBTLimit );
     Abc_Print( -2, "\t-F num : the number of timeframes in inductive case [default = %d]\n", pPars->nFrames );
@@ -36952,6 +36958,7 @@ usage:
     Abc_Print( -2, "\t-e     : toggle using equivalences as choices [default = %s]\n", pPars->fMakeChoices? "yes": "no" );
     Abc_Print( -2, "\t-c     : toggle using circuit-based SAT solver [default = %s]\n", pPars->fUseCSat? "yes": "no" );
     Abc_Print( -2, "\t-q     : toggle quitting when PO is not a constant candidate [default = %s]\n", pPars->fStopWhenGone? "yes": "no" );
+    Abc_Print( -2, "\t-o     : toggle calling old engine [default = %s]\n", fUseOld? "yes": "no" );
     Abc_Print( -2, "\t-w     : toggle printing verbose info about equivalent flops [default = %s]\n", pPars->fVerboseFlops? "yes": "no" );
     Abc_Print( -2, "\t-v     : toggle printing verbose information [default = %s]\n", pPars->fVerbose? "yes": "no" );
     Abc_Print( -2, "\t-h     : print the command usage\n");
diff --git a/src/base/abci/abcScorr.c b/src/base/abci/abcScorr.c
index f224a0fd4..e228f37d2 100644
--- a/src/base/abci/abcScorr.c
+++ b/src/base/abci/abcScorr.c
@@ -444,6 +444,36 @@ Abc_Ntk_t * Abc_NtkTestScorr( char * pFileNameIn, char * pFileNameOut, int nStep
     return pResult;
 }
 
+/**Function*************************************************************
+
+  Synopsis    []
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+Gia_Man_t * Cec_ManScorrCorrespondence( Gia_Man_t * p, Cec_ParCor_t * pCorPars )
+{
+    Gia_Man_t * pRes = NULL;
+    Aig_Man_t * pOld, * pNew;
+    Ssw_Pars_t SswPars, * pSswPars = &SswPars;
+    Ssw_ManSetDefaultParams( pSswPars );
+    pSswPars->nBTLimit   = pCorPars->nBTLimit;
+    pSswPars->nFramesK   = pCorPars->nFrames;
+    pSswPars->fLatchCorr = pCorPars->fLatchCorr;
+    pSswPars->fVerbose   = pCorPars->fVerbose;
+    pOld = Gia_ManToAigSimple( p );
+    pNew = Ssw_SignalCorrespondence( pOld, pSswPars );
+    pRes = Gia_ManFromAigSimple( pNew );
+    Gia_ManReprFromAigRepr( pOld, p );
+    Aig_ManStop( pOld );
+    Aig_ManStop( pNew );
+    return pRes;
+}
+
 
 ////////////////////////////////////////////////////////////////////////
 ///                       END OF FILE                                ///